diff options
Diffstat (limited to 'src/include/taler_crypto_lib.h')
| -rw-r--r-- | src/include/taler_crypto_lib.h | 180 |
1 files changed, 140 insertions, 40 deletions
diff --git a/src/include/taler_crypto_lib.h b/src/include/taler_crypto_lib.h index 39de34b8a..d5024e6c8 100644 --- a/src/include/taler_crypto_lib.h +++ b/src/include/taler_crypto_lib.h @@ -396,7 +396,83 @@ int TALER_test_coin_valid (const struct TALER_CoinPublicInfo *coin_public_info); -/* ****************** Refresh crypto primitives ************* */ +GNUNET_NETWORK_STRUCT_BEGIN + +/** + * Header for serializations of coin-specific information about the + * fresh coins we generate. These are the secrets that arise during + * planchet generation, which is the first stage of creating a new + * coin. + */ +struct TALER_PlanchetSecretsP +{ + + /** + * Private key of the coin. + */ + struct TALER_CoinSpendPrivateKeyP coin_priv; + + /** + * The blinding key. + */ + struct TALER_DenominationBlindingKeyP blinding_key; + +}; + +GNUNET_NETWORK_STRUCT_END + + +/** + * Details about a planchet that the customer wants to obtain + * a withdrawal authorization. This is the information that + * will need to be sent to the exchange to obtain the blind + * signature required to turn a planchet into a coin. + */ +struct TALER_PlanchetDetail +{ + /** + * Hash of the denomination public key. + */ + struct GNUNET_HashCode denom_pub_hash; + + /** + * Hash of the coin's public key. Kept around so we do not need to + * compute it again. Can be recomputed by hashing the public key + * of @a coin_priv if storage is at a premium. + */ + struct GNUNET_HashCode c_hash; + + /** + * Blinded coin (see GNUNET_CRYPTO_rsa_blind()). Note: is malloc()'ed! + */ + char *coin_ev; + + /** + * Number of bytes in @a coin_ev. + */ + size_t coin_ev_size; +}; + + +/** + * Information about a (fresh) coin, returned from the API when we + * finished creating a coin. Note that @e sig needs to be freed + * using the appropriate code. + */ +struct TALER_FreshCoin +{ + + /** + * The exchange's signature over the coin's public key. + */ + struct TALER_DenominationSignature sig; + + /** + * The coin's private key. + */ + struct TALER_CoinSpendPrivateKeyP coin_priv; + +}; GNUNET_NETWORK_STRUCT_BEGIN @@ -426,6 +502,7 @@ struct TALER_TransferSecretP */ #define TALER_WIRE_TRANSFER_IDENTIFIER_LEN_STR "32" + /** * Raw value of a wire transfer subjects, without the checksum. */ @@ -472,6 +549,68 @@ struct TALER_WireTransferIdentifierP GNUNET_NETWORK_STRUCT_END + +/** + * Setup information for a fresh coin, deriving the coin private key + * and the blinding factor from the @a secret_seed with a KDF salted + * by the @a coin_num_salt. + * + * @param secret_seed seed to use for KDF to derive coin keys + * @param coin_num_salt number of the coin to include in KDF + * @param[out] fc value to initialize + */ +void +TALER_planchet_setup_refresh (const struct TALER_TransferSecretP *secret_seed, + unsigned int coin_num_salt, + struct TALER_PlanchetSecretsP *fc); + + +/** + * Setup information for a fresh coin. + * + * @param[out] ps value to initialize + */ +void +TALER_planchet_setup_random (struct TALER_PlanchetSecretsP *ps); + + +/** + * Prepare a planchet for tipping. Creates and blinds a coin. + * + * @param dk denomination key for the coin to be created + * @param ps secret planchet internals (for #TALER_planchet_to_coin) + * @param[out] pd set to the planchet detail for TALER_MERCHANT_tip_pickup() and + * other withdraw operations + * @return #GNUNET_OK on success + */ +int +TALER_planchet_prepare (const struct TALER_DenominationPublicKey *dk, + const struct TALER_PlanchetSecretsP *ps, + struct TALER_PlanchetDetail *pd); + + +/** + * Obtain a coin from the planchet's secrets and the blind signature + * of the exchange. + * + * @param dk denomination key, must match what was given to #TALER_planchet_prepare() + * @param blind_sig blind signature from the exchange + * @param ps secrets from #TALER_planchet_prepare() + * @param c_hash hash of the coin's public key for verification of the signature + * @param[out] coin set to the details of the fresh coin + * @return #GNUNET_OK on success + */ +int +TALER_planchet_to_coin (const struct TALER_DenominationPublicKey *dk, + const struct GNUNET_CRYPTO_RsaSignature *blind_sig, + const struct TALER_PlanchetSecretsP *ps, + const struct GNUNET_HashCode *c_hash, + struct TALER_FreshCoin *coin); + + +/* ****************** Refresh crypto primitives ************* */ + + /** * Given the coin and the transfer private keys, compute the * transfer secret. (Technically, we only need one of the two @@ -516,44 +655,5 @@ TALER_link_recover_transfer_secret (const struct TALER_TransferPublicKeyP *trans const struct TALER_CoinSpendPrivateKeyP *coin_priv, struct TALER_TransferSecretP *transfer_secret); -GNUNET_NETWORK_STRUCT_BEGIN - -/** - * Header for serializations of coin-specific information about the - * fresh coins we generate during a melt. - */ -struct TALER_PlanchetSecretsP -{ - - /** - * Private key of the coin. - */ - struct TALER_CoinSpendPrivateKeyP coin_priv; - - /** - * The blinding key. - */ - struct TALER_DenominationBlindingKeyP blinding_key; - -}; - -GNUNET_NETWORK_STRUCT_END - - -/** - * Setup information for a fresh coin, deriving the coin private key - * and the blinding factor from the @a secret_seed with a KDF salted - * by the @a coin_num_salt. - * - * @param secret_seed seed to use for KDF to derive coin keys - * @param coin_num_salt number of the coin to include in KDF - * @param[out] fc value to initialize - */ -void -TALER_planchet_setup_refresh (const struct TALER_TransferSecretP *secret_seed, - unsigned int coin_num_salt, - struct TALER_PlanchetSecretsP *fc); - - #endif |